1. Field of the Invention
The present invention relates to image processing wherein image data are divided into multiple regions based on the feature extraction of image data.
2. Description of Related Art
Documents used in image processing devices include documents that consist of multiple images with various attributes such as character images, halftone dot images, and photographic images. It is, therefore, desirable to perform image processing most suited for the particular attribute of a particular image. It is necessary to perform regional recognition for dividing image data into regions by attributes, exactly.
The technique of dividing image data into halftone dot regions, photographic regions, character regions, and graphic regions has been known.
Halftone dot regions can be divided into halftone dot graphic regions, i.e., regions where graphics consist of halftone dots, and halftone dot photographic regions, i.e., regions where photographs consist of halftone dots. However, there has been no known technology for separating them.
For example, in an image processing system wherein images within halftone dot graphic regions are vector transformed and outputted by filling each closed region with a solid color, images in a halftone dot photographic region are also vector transformed as images in a halftone dot graphic region. Therefore, the gradation of the images in the halftone dot photographic region become deteriorated, and the images of the halftone dot photographic region become transformed into images like illustration.